Oxidative stress has been associated with a number of physiological problems in swine,including reduced production efficiency.Recently,although there has been increased research into regulatory mechanisms and antioxid...Oxidative stress has been associated with a number of physiological problems in swine,including reduced production efficiency.Recently,although there has been increased research into regulatory mechanisms and antioxidant strategies in relation to oxidative stress-induced pig production,it remains so far largely unsuccessful to develop accurate models and nutritional strategies for specific oxidative stress factors.Here,we discuss the dose and dose intensity of the causes of oxidative stress involving physiological,environmental and dietary factors,recent research models and the antioxidant strategies to provide theoretical guidance for future oxidative stress research in swine.展开更多
Simulating the total ionizing dose(TID)of an electrical system using transistor-level models can be difficult and expensive,particularly for digital-integrated circuits(ICs).In this study,a method for modeling TID eff...Simulating the total ionizing dose(TID)of an electrical system using transistor-level models can be difficult and expensive,particularly for digital-integrated circuits(ICs).In this study,a method for modeling TID effects in complementary metaloxide semiconductor(CMOS)digital ICs based on the input/output buffer information specification(IBIS)was proposed.The digital IC was first divided into three parts based on its internal structure:the input buffer,output buffer,and functional area.Each of these three parts was separately modeled.Using the IBIS model,the transistor V-I characteristic curves of the buffers were processed,and the physical parameters were extracted and modeled using VHDL-AMS.In the functional area,logic functions were modeled in VHDL according to the data sheet.A golden digital IC model was developed by combining the input buffer,output buffer,and functional area models.Furthermore,the golden ratio was reconstructed based on TID experimental data,enabling the assessment of TID effects on the threshold voltage,carrier mobility,and time series of the digital IC.TID experiments were conducted using a CMOS non-inverting multiplexer,NC7SZ157,and the results were compared with the simulation results,which showed that the relative errors were less than 2%at each dose point.This confirms the practicality and accuracy of the proposed modeling method.The TID effect model for digital ICs developed using this modeling technique includes both the logical function of the IC and changes in electrical properties and functional degradation impacted by TID,which has potential applications in the design of radiation-hardening tolerance in digital ICs.展开更多
X-ray excited photodynamic therapy(X-PDT)is the bravo answer of photodynamic therapy(PDT)for deep-seated tumors,as it employs X-ray as the irradiation source to overcome the limitation of light penetration depth.Howev...X-ray excited photodynamic therapy(X-PDT)is the bravo answer of photodynamic therapy(PDT)for deep-seated tumors,as it employs X-ray as the irradiation source to overcome the limitation of light penetration depth.However,high X-ray irradiation dose caused organ lesions and side effects became the major barrier to X-PDT application.To address this issue,this work employed a classic-al co-precipitation reaction to synthesize NaLuF_(4):15%Tb^(3+)(NLF)with an average particle size of(23.48±0.91)nm,which was then coupled with the photosensitizer merocyanine 540(MC540)to form the X-PDT system NLF-MC540 with high production of singlet oxygen.The system could induce antitumor efficacy to about 24%in relative low dose X-ray irradiation range(0.1-0.3 Gy).In vivo,when NLF-MC540 irradiated by 0.1 Gy X-ray,the tumor inhibition percentage reached 89.5%±5.7%.The therapeutic mechanism of low dose X-PDT was found.A significant increase of neutrophils in serum was found on the third day after X-PDT.By immunohistochemical staining of tumor sections,the Ly6G^(+),CD8^(+),and CD11c^(+)cells infiltrated in the tumor microenvironment were studied.Utilizing the bilat-eral tumor model,the NLF-MC540 with 0.1 Gy X-ray irradiation could inhibit both the primary tumor and the distant tumor growth.De-tected by enzyme linked immunosorbent assay(ELISA),two cytokines IFN-γand TNF-αin serum were upregulated 7 and 6 times than negative control,respectively.Detected by enzyme linked immune spot assay(ELISPOT),the number of immune cells attributable to the IFN-γand TNF-αlevels in the group of low dose X-PDT were 14 and 6 times greater than that in the negative control group,respectively.Thus,it conclude that low dose X-PDT system could successfully upregulate the levels of immune cells,stimulate the secretion of cy-tokines(especially IFN-γand TNF-α),activate antitumor immunity,and finally inhibit colon tumor growth.展开更多
Timer error as well as its convention is very important for dose accuracy during irradiation. This paper determines the timer error of irradiators at Secondary Standard Dosimetry Laboratory (SSDL) in Nigeria. The irra...Timer error as well as its convention is very important for dose accuracy during irradiation. This paper determines the timer error of irradiators at Secondary Standard Dosimetry Laboratory (SSDL) in Nigeria. The irradiators are Cs-137 OB6 irradiator and X-ray irradiators at the Protection level SSDL;and Co-60 irradiator at the Therapy Level SSDL. PTW UNIDOS electrometer and LS01 Ionization chamber were used at the Protection Level to obtain doses for both Cs-137 OB6 and X-ray irradiators while an IBA farmer type ionization chamber and an IBA DOSE 1 electrometer were used at the Protection Level SSDL. Single/multiple exposure method and graphical method were used in the determination of the timer error for the three irradiators. The timer error obtained for Cs-137 OB6 irradiator was 0.48 ± 0.01 s, the timer error for the X-ray irradiator was 0.09 ± 0.01 s while the timer error obtained for GammaBeam X200 was 1.21 ± 0.04 s. It was observed that the timer error is not affected by source to detector distance. It was also observed that the timer error of Co-60 Gamma X200 irradiator is increasing with the age of the machine. Source to detector distance and field size do not contribute towards the timer error of the irradiators. The timer error of the Co-60 Gamma X200 irradiator (the only irradiator among the irradiators with a pneumatic system) increases with the age of the irradiator.展开更多
The Uranium-238 (<sup>238</sup>U), Thorium-232 (<sup>232</sup>Th) families and Potassium-40 (<sup>40</sup>K) are of terrestrial origin and contribute generally to an individual’s e...The Uranium-238 (<sup>238</sup>U), Thorium-232 (<sup>232</sup>Th) families and Potassium-40 (<sup>40</sup>K) are of terrestrial origin and contribute generally to an individual’s external exposure through our presence in this environment. They also contribute to the internal exposure through the ingestion of products and beverages such as water that are close to the earth. The aim of this work is to determine the committed effective dose or Total Indicative Dose (TID) due to gamma radioactivity of the borehole water from the Nord Riviera (NR) well field operated by the Côte d’Ivoire Water Distribution Company (SODECI) for the supply of drinking water to part of the population of Abidjan. In addition, the populations, with their habits, could use these borehole waters directly as drinking water. To this end, water samples from the seven (07) functional boreholes were collected and analyzed on a gamma spectrometry chain, equipped with an HPGe detector in the laboratory of the Radiation Protection Institute (RPI) of the GHANA Atomic Energy Commission (GAEC). The results of the specific activities of <sup>238</sup>U, <sup>232</sup>Th and <sup>40</sup>K obtained were transcribed into TID. As the natural radioactivity of the borehole water is high [1], the TIDs calculated from the activity results of the natural radionuclides<sup>238</sup>U, <sup>232</sup>Th, and <sup>40</sup>K vary for the seven boreholes from 0.150 to 0.166 mSv/yr with an average of 0.161 ± 0.034 mSv/yr. The TID of the control tower, where the borehole water is mixed and treated for household use, is equal to 0.136 ± 0.03 mSv/yr. The TIDs obtained are therefore all slightly greater than the WHO reference dose value of 0.1 mSv/yr. But all remain below the UNSCEAR reference dose of 0.29 mSv/yr.展开更多
Objective: The current research study aims to calculate entrance surface air kerma for skull, chest, cervical spine, lumbar spine, and pelvic X-ray examinations in interior posterior and posterior interior positions a...Objective: The current research study aims to calculate entrance surface air kerma for skull, chest, cervical spine, lumbar spine, and pelvic X-ray examinations in interior posterior and posterior interior positions and generate a method for chest dose reduction to decrease radiation risk. Materials and Methods: The indirect dose measurement was used in the current research. The X-ray tube output was measured using RAD-CHECK Plus ionization chamber and the indirect entrance surface air kerma was calculated via applying physical acquisition parameters such as a focus on skin distance, tube current times exposure time (mAs), and applied tube voltage (kV), and applying a mathematical model. Results: The main findings were obtained from comparing the radiation doses with the reference levels of International organizations such as the American College of Radiology and the International Atomic Energy Authority. The mean entrance skin dose for the skull (AP), skull (PA), skull (LAT), cervical spine (PA), cervical spine (LAT), lumbar spine (AP), lumbar spine (LAT), pelvis (AP), and pelvis (LAT) of adult X-ray examinations was within the diagnostic reference dose level values obtained by ACR (2018) except for the ESD for chest (AP) which was 0.88 mGy. Conclusions: The results of the study concluded that by adjusting the applied tube voltage, kV, and tube current product time, mAs decreased the radiation dose to the chest X-ray by 58%.展开更多
Purpose: This study aimed to compare the survival benefits between different total radiation doses in definitive chemoradiotherapy (dCRT) for inoperable esophageal carcinoma (EC) based on modern radiotherapy technique...Purpose: This study aimed to compare the survival benefits between different total radiation doses in definitive chemoradiotherapy (dCRT) for inoperable esophageal carcinoma (EC) based on modern radiotherapy techniques. Methods: A systematic review was performed by searching the databases of PubMed, EMBASE, Cochrane Central Register of Controlled Trials and Web of Science. All studies published prior to November 30, 2022, comparing radiation dose and disease-related outcomes in EC patients. The hazard ratio (HR) and odds ratio (OR) were used to describe the risk of outcomes and toxicities. Results: Seven prospective trials involving 1124EC patients were enrolled for analyses. The results revealed that the effect on overall survival (HR = 0.99, 95% CI = 0.85 - 1.16, P = 0.94), local progression-free survival (HR = 0.83, 95% CI = 0.58 - 1.17, P = 0.29), local regional progression-free survival (HR = 0.94, 95% CI = 0.76 - 1.17, P = 0.61), progression-free survival (HR = 0.90, 95% CI = 0.71 - 1.13, P = 0.35) was similar in the high-dose and standard-dose groups. Additionally, a high radiation dose exhibited a potential disadvantage in respiratory toxicities when compared with a standard dose (4.8% vs 2.2%, OR 2.11, P = 0.06). Conclusions: The efficacy of the HD group (≥60 Gy) and the SD group (approximately 50 Gy) for inoperable local advanced EC was similar. However, the HD group exhibited a high radiation dose exhibited a potential disadvantage in respiratory toxicities when compared with a standard dose. Simultaneously, the final results of several ongoing prospective trials regarding the optimal radiation dose in dCRT are awaited.展开更多
Objective:To explore the half-effective dose(ED_(50))of remazolam toluenesulfonate combined with subthreshold amounts of esketamine for inhibiting cardiovascular response to tracheal intubation in elderly patients.Met...Objective:To explore the half-effective dose(ED_(50))of remazolam toluenesulfonate combined with subthreshold amounts of esketamine for inhibiting cardiovascular response to tracheal intubation in elderly patients.Method:We included 42 patients,aged 65-75,who required general anesthesia and single-lumen endotracheal intubation for elective surgery.The first patient was administered remazolam toluenesulfonate at a dose of 0.20 mg/kg.Once the patient lost consciousness,their alertness/sedation score(OAA/S score)was≤1,and their BIS score was≤60,and a subthreshold dose(0.3 mg/kg)of esketamine was given.The subsequent doses were adjusted using a sequential approach based on the cardiovascular response to tracheal intubation observed in the previous patient.The dose was modified in increments or decrements of 0.01 mg/kg.The ED_(50)and 95%CI of remazolam toluenesulfonate were calculated using the Dixon and Massey sequential distribution test method.Result:The inhibition of endotracheal intubation response was positively correlated with the dose of remazolam toluenesulfonate,and the depth of sedation could not be achieved when the amount was≤0.22 mg/kg.The ED_(50)of remazolam toluenesulfonate combined with a subthreshold dose of esketamine in inhibiting cardiovascular response to tracheal intubation in elderly patients was 0.30(0.28,0.33)mg/kg.There was no statistically significant difference in blood pressure between the induction of anesthesia and before the operation.Conclusion:When compounded with 0.3 mg/kg esketamine,the ED_(50)of Remazolam toluenesulfonate in inhibiting cardiovascular response to endotracheal intubation in elderly patients was 0.30 mg/kg(95%CI0.28-0.33 mg/kg).展开更多
In recent years,graphics processing units(GPUs)have been applied to accelerate Monte Carlo(MC)simulations for proton dose calculation in radiotherapy.Nonetheless,current GPU platforms,such as Compute Unified Device Ar...In recent years,graphics processing units(GPUs)have been applied to accelerate Monte Carlo(MC)simulations for proton dose calculation in radiotherapy.Nonetheless,current GPU platforms,such as Compute Unified Device Architecture(CUDA)and Open Computing Language(OpenCL),suffer from cross-platform limitation or relatively high programming barrier.However,the Taichi toolkit,which was developed to overcome these difficulties,has been successfully applied to high-performance numerical computations.Based on the class II condensed history simulation scheme with various proton-nucleus interactions,we developed a GPU-accelerated MC engine for proton transport using the Taichi toolkit.Dose distributions in homogeneous and heterogeneous geometries were calculated for 110,160,and 200 MeV protons and were compared with those obtained by full MC simulations using TOPAS.The gamma passing rates were greater than 0.99 and 0.95 with criteria of 2 mm,2%and 1 mm,1%,respectively,in all the benchmark tests.Moreover,the calculation speed was at least 5800 times faster than that of TOPAS,and the number of lines of code was approximately 10 times less than those of CUDA or OpenCL.Our study provides a highly accurate,efficient,and easy-to-use proton dose calculation engine for fast prototyping,beamlet calculation,and education purposes.展开更多
Compton camera-based prompt gamma(PG) imaging has been proposed for range verification during proton therapy. However, a deviation between the PG and dose distributions, as well as the difference between the reconstru...Compton camera-based prompt gamma(PG) imaging has been proposed for range verification during proton therapy. However, a deviation between the PG and dose distributions, as well as the difference between the reconstructed PG and exact values, limit the effectiveness of the approach in accurate range monitoring during clinical applications. The aim of the study was to realize a PG-based dose reconstruction with a Compton camera, thereby further improving the prediction accuracy of in vivo range verification and providing a novel method for beam monitoring during proton therapy. In this paper, we present an approach based on a subset-driven origin ensemble with resolution recovery and a double evolutionary algorithm to reconstruct the dose depth profile(DDP) from the gamma events obtained by a cadmium-zinc-telluride Compton camera with limited position and energy resolution. Simulations of proton pencil beams with clinical particle rate irradiating phantoms made of different materials and the CT-based thoracic phantom were used to evaluate the feasibility of the proposed method. The results show that for the monoenergetic proton pencil beam irradiating homogeneous-material box phantom,the accuracy of the reconstructed DDP was within 0.3 mm for range prediction and within 5.2% for dose prediction. In particular, for 1.6-Gy irradiation in the therapy simulation of thoracic tumors, the range deviation of the reconstructed spreadout Bragg peak was within 0.8 mm, and the relative dose deviation in the peak area was less than 7% compared to the exact values. The results demonstrate the potential and feasibility of the proposed method in future Compton-based accurate dose reconstruction and range verification during proton therapy.展开更多
Monte Carlo simulations are frequently utilized in radiation dose assessments.However,many researchers find the prevailing computing platforms to be intricate.This highlights a pressing need for a specialized framewor...Monte Carlo simulations are frequently utilized in radiation dose assessments.However,many researchers find the prevailing computing platforms to be intricate.This highlights a pressing need for a specialized framework for phantom dose evalua-tion.To address this gap,we developed a user-friendly radiation dose assessment platform using the Monte Carlo toolkit,Geant4.The Tsinghua University Phantom Dose(THUDosePD)augments the flexibility of Monte Carlo simulations in dosi-metric research.Originating from THUDose,a code with generic,functional,and application layers,THUDosePD focuses predominantly on anatomical phantom dose assessment.Additionally,it enables medical exposure simulation,intricate geometry creation,and supports both three-dimensional radiation dose analysis and phantom format transformations.The system operates on a multi-threaded parallel CPU architecture,with some modules enhanced for GPU parallel computing.Benchmark tests on the ICRP reference male illustrated the capabilities of THUDosePD in phantom dose assessment,covering the effective dose,three-dimensional dose distribution,and three-dimensional organ dose.We also conducted a voxelization conversion on the polygon mesh phantom,demonstrating the method’s efficiency and consistency.Extended applications based on THUDosePD further underline its broad adaptability.This intuitive,three-dimensional platform stands out as a valuable tool for phantom radiation dosimetry research.展开更多
Objective:To assess the clinical outcomes and toxicities of once daily(QD)simultaneous dose reduction intensity-modulated radiotherapy(SDR-IMRT-QD;SDR-QD)versus conventional QD IMRT(C-QD)and twice daily(BID)IMRT in pa...Objective:To assess the clinical outcomes and toxicities of once daily(QD)simultaneous dose reduction intensity-modulated radiotherapy(SDR-IMRT-QD;SDR-QD)versus conventional QD IMRT(C-QD)and twice daily(BID)IMRT in patients with limited-stage small cell lung cancer(LS-SCLC).Methods:After propensity score matching(PSM),a retrospective analysis involving 300 patients with LS-SCLC treated using SDR-QD,C-QD,or BID was performed from January 1,2014 to December 31,2019.The prescribed irradiation dose in the SDR-QD cohort was 60 Gy/PGTV and 54 Gy/PTV QD.The radiation dose was 60 Gy for both PGTV and PTV QD in the C-QD cohort.The radiation dose was 45 Gy for both PGTV and PTV in the BID cohort.Toxicities,short-term effects,and survival outcomes were recorded.A meta-analysis on the protective effects of pharmaceuticals for cardiac toxicities induced by anti-tumor therapy was performed.Results:The median overall survival time(MST)in the 3 cohorts were 32.7 months(SDR-QD),26.3 months(C-QD),and 33.6 months(BID);the differences between groups were statistically significant.Lower toxicities and doses to organs-at-risk(OARs)occurred in the SDR-QD and BID cohorts.Further,the cardiac dose dosimetric parameter Vheart40 was negatively associated with survival(r=-0.35,P=0.007).A Vheart40 value of 16.5%was recommended as a cut-off point,which yielded 54.7%sensitivity and 85.7%specificity for predicting negative survival outcomes.The meta-analysis indicated that pharmaceuticals significantly reduced the cardiac toxicities induced by chemotherapy,but not radiotherapy.Conclusions:SDR-QD was shown to have similar toxicities and survival compared with BID,but fewer toxicities and better survival than C-QD.In addition,cardiac dose exposure was negatively associated with survival.Thus,16.5%of the cardiac dosimetric parameter Vheart40 is recommended as the cut-off point,and a Vheart40>16.5%predicts poor survival.展开更多
The total ionizing dose(TID) effect is a key cause for the degradation/failure of semiconductor device performance under energetic-particle irradiation. We developed a dynamic model of mobile particles and defects by ...The total ionizing dose(TID) effect is a key cause for the degradation/failure of semiconductor device performance under energetic-particle irradiation. We developed a dynamic model of mobile particles and defects by solving the rate equations and Poisson's equation simultaneously, to understand threshold voltage shifts induced by TID in silicon-based metal–oxide–semiconductor(MOS) devices. The calculated charged defect distribution and corresponding electric field under different TIDs are consistent with experiments. TID changes the electric field at the Si/SiO_(2) interface by inducing the accumulation of oxide charged defects nearby, thus shifting the threshold voltage accordingly. With increasing TID, the oxide charged defects increase to saturation, and the electric field increases following the universal 2/3 power law. Through analyzing the influence of TID on the interfacial electric field by different factors, we recommend that the radiation-hardened performance of devices can be improved by choosing a thin oxide layer with high permittivity and under high gate voltages.展开更多
Workers who conduct regular facility inspections in radioactive environments will inevitably be affected by radiation.Therefore,it is important to optimize the inspection path to ensure that workers are exposed to the...Workers who conduct regular facility inspections in radioactive environments will inevitably be affected by radiation.Therefore,it is important to optimize the inspection path to ensure that workers are exposed to the least amount of radiation.This study proposes a discrete Rao-combined artificial bee colony(ABC)algorithm for planning inspection paths with minimum exposure doses in radioactive environments with obstacles.In this algorithm,retaining the framework of the traditional ABC algorithm,we applied the directional solution update rules of Rao algorithms at the employed bee stage and onlooker bee stage to increase the exploitation ability of the algorithm and implement discretion using the swap operator and swap sequence.To increase the randomness of solution generation,the chaos algorithm was used at the initialization stage.The K-opt operation technique was introduced at the scout bee stage to increase the exploration ability of the algorithm.For path planning in an environment with complex structural obstacles,an obstacle detour technique using a recursive algorithm was applied.To evaluate the performance of the proposed algorithm,we performed experimental simulations in three hypothetical environments and compared the results with those of improved particle swarm optimization,chaos particle swarm optimization,improved ant colony optimization,and discrete Rao’s algorithms.The experimental results show the high performance of the proposed discrete Rao-combined ABC algorithm and its obstacle detour capability.展开更多
Objective The study aimed to estimate the benchmark dose(BMD)of coke oven emissions(COEs)exposure based on mitochondrial damage with the mitochondrial DNA copy number(mtDNAcn)as a biomarker.Methods A total of 782 subj...Objective The study aimed to estimate the benchmark dose(BMD)of coke oven emissions(COEs)exposure based on mitochondrial damage with the mitochondrial DNA copy number(mtDNAcn)as a biomarker.Methods A total of 782 subjects were recruited,including 238 controls and 544 exposed workers.The mtDNAcn of peripheral leukocytes was detected through the real-time fluorescence-based quantitative polymerase chain reaction.Three BMD approaches were used to calculate the BMD of COEs exposure based on the mitochondrial damage and its 95%confidence lower limit(BMDL).Results The mtDNAcn of the exposure group was lower than that of the control group(0.60±0.29 vs.1.03±0.31;P<0.001).A dose-response relationship was shown between the mtDNAcn damage and COEs.Using the Benchmark Dose Software,the occupational exposure limits(OELs)for COEs exposure in males was 0.00190 mg/m^(3).The OELs for COEs exposure using the BBMD were 0.00170 mg/m^(3)for the total population,0.00158 mg/m^(3)for males,and 0.00174 mg/m^(3)for females.In possible risk obtained from animal studies(PROAST),the OELs of the total population,males,and females were 0.00184,0.00178,and 0.00192 mg/m^(3),respectively.Conclusion Based on our conservative estimate,the BMDL of mitochondrial damage caused by COEs is0.002 mg/m^(3).This value will provide a benchmark for determining possible OELs.展开更多
Computed Tomography(CT)images have been extensively employed in disease diagnosis and treatment,causing a huge concern over the dose of radiation to which patients are exposed.Increasing the radiation dose to get a be...Computed Tomography(CT)images have been extensively employed in disease diagnosis and treatment,causing a huge concern over the dose of radiation to which patients are exposed.Increasing the radiation dose to get a better image may lead to the development of genetic disorders and cancer in the patients;on the other hand,decreasing it by using a Low-Dose CT(LDCT)image may cause more noise and increased artifacts,which can compromise the diagnosis.So,image reconstruction from LDCT image data is necessary to improve radiologists’judgment and confidence.This study proposed three novel models for denoising LDCT images based on Wasserstein Generative Adversarial Network(WGAN).They were incorporated with different loss functions,including Visual Geometry Group(VGG),Structural Similarity Loss(SSIM),and Structurally Sensitive Loss(SSL),to reduce noise and preserve important information on LDCT images and investigate the effect of different types of loss functions.Furthermore,experiments have been conducted on the Graphical Processing Unit(GPU)and Central Processing Unit(CPU)to compare the performance of the proposed models.The results demonstrated that images from the proposed WGAN-SSIM,WGAN-VGG-SSIM,and WGAN-VGG-SSL were denoised better than those from state-of-the-art models(WGAN,WGAN-VGG,and SMGAN)and converged to a stable equilibrium compared with WGAN and WGAN-VGG.The proposed models are effective in reducing noise,suppressing artifacts,and maintaining informative structure and texture details,especially WGAN-VGG-SSL which achieved a high peak-signalto-noise ratio(PNSR)on both GPU(26.1336)and CPU(25.8270).The average accuracy of WGAN-VGG-SSL outperformed that of the state-ofthe-art methods by 1 percent.Experiments prove that theWGAN-VGG-SSL is more stable than the other models on both GPU and CPU.展开更多
Laser-assisted simulation technique has played a crucial role in the investigation of dose rate effects of silicon-based devices and integrated circuits,due to its exceptional advantages in terms of flexibility,safety...Laser-assisted simulation technique has played a crucial role in the investigation of dose rate effects of silicon-based devices and integrated circuits,due to its exceptional advantages in terms of flexibility,safety,convenience,and precision.In recent years,wide band gap materials,known for their strong bonding and high ionization energy,have gained increasing attention from researchers and hold significant promise for extensive applications in specialized environments.Consequently,there is a growing need for comprehensive research on the dose rate effects of wide band gap materials.In response to this need,the use of laser-assisted simulation technology has emerged as a promising approach,offering an effective means to assess the efficacy of investigating these materials and devices.This paper focused on investigating the feasibility of laser-assisted simulation to study the dose rate effects of wide band gap semiconductor devices.Theoretical conversion factors for laser-assisted simulation of dose rate effects of GaN-based and SiC-based devices were been provided.Moreover,to validate the accuracy of the conversion factors,pulsed laser and dose rate experiments were conducted on GaN-based and SiC-based PIN diodes.The results demonstrate that pulsed laser radiation andγ-ray radiation can produce highly similar photocurrent responses in GaN-based and SiC-based PIN diodes,with correlation coefficients of 0.98 and 0.974,respectively.This finding reaffirms the effectiveness of laser-assisted simulation technology,making it a valuable complement in studying the dose rate effects of wide band gap semiconductor devices.展开更多
BACKGROUND Treatment of infantile-onset inflammatory bowel disease(IO-IBD)is often challenging due to its aggressive disease course and failure of standard therapies with a need for biologics.Secondary loss of respons...BACKGROUND Treatment of infantile-onset inflammatory bowel disease(IO-IBD)is often challenging due to its aggressive disease course and failure of standard therapies with a need for biologics.Secondary loss of response is frequently caused by the production of anti-drug antibodies,a well-known problem in IBD patients on biologic treatment.We present a case of IO-IBD treated with therapeutic drug monitoring(TDM)-guided high-dose anti-tumor necrosis factor therapy,in which dose escalation monitoring was used as a strategy to overcome anti-drug antibodies.CASE SUMMARY A 5-mo-old boy presented with a history of persistent hematochezia from the 10th d of life,as well as relapsing perianal abscess and growth failure.Hypoalbuminemia,anemia,and elevated inflammatory markers were also present.Endoscopic assessment revealed skip lesions with deep colic ulcerations,inflammatory anal sub-stenosis,and deep fissures with persistent abscess.A diagnosis of IO-IBD Crohn-like was made.The patient was initially treated with oral steroids and fistulotomy.After the perianal abscess healed,adalimumab(ADA)was administered with concomitant gradual tapering of steroids.Clinical and biochemical steroid-free remission was achieved with good trough levels.After 3 mo,antibodies to ADA(ATA)were found with undetectable trough levels;therefore,we optimized the therapy schedule,first administering 10 mg weekly and subsequently up to 20 mg weekly(2.8 mg/kg/dose).After 2 mo of high-dose treatment,ATA disappeared,with concomitant high trough levels and stable clinical and biochemical remission of the disease.CONCLUSION TDM-guided high-dose ADA treatment as a monotherapy overcame ATA production.This strategy could be a good alternative to combination therapy,especially in very young patients.展开更多
基金supported by Guangzhou Science and Technology Planning Project(2023A04J0131)Special fund for scientific innovation strategyconstruction of high level Academy of Agriculture Science(R2020PY-JG009,R2022PY-QY007,202106TD)+2 种基金China Agriculture Research System-CARS-35the Project of Swine Innovation Team in Guangdong Modern Agricultural Research System(2022KJ126)Special Fund for Rural Revitalization Strategy of Guangdong(2023TS-3),China。
文摘Oxidative stress has been associated with a number of physiological problems in swine,including reduced production efficiency.Recently,although there has been increased research into regulatory mechanisms and antioxidant strategies in relation to oxidative stress-induced pig production,it remains so far largely unsuccessful to develop accurate models and nutritional strategies for specific oxidative stress factors.Here,we discuss the dose and dose intensity of the causes of oxidative stress involving physiological,environmental and dietary factors,recent research models and the antioxidant strategies to provide theoretical guidance for future oxidative stress research in swine.
基金This work was supported by the special fund of the State Key Laboratory of Intense Pulsed Radiation Simulation and Effect(No.SKLIPR2011).
文摘Simulating the total ionizing dose(TID)of an electrical system using transistor-level models can be difficult and expensive,particularly for digital-integrated circuits(ICs).In this study,a method for modeling TID effects in complementary metaloxide semiconductor(CMOS)digital ICs based on the input/output buffer information specification(IBIS)was proposed.The digital IC was first divided into three parts based on its internal structure:the input buffer,output buffer,and functional area.Each of these three parts was separately modeled.Using the IBIS model,the transistor V-I characteristic curves of the buffers were processed,and the physical parameters were extracted and modeled using VHDL-AMS.In the functional area,logic functions were modeled in VHDL according to the data sheet.A golden digital IC model was developed by combining the input buffer,output buffer,and functional area models.Furthermore,the golden ratio was reconstructed based on TID experimental data,enabling the assessment of TID effects on the threshold voltage,carrier mobility,and time series of the digital IC.TID experiments were conducted using a CMOS non-inverting multiplexer,NC7SZ157,and the results were compared with the simulation results,which showed that the relative errors were less than 2%at each dose point.This confirms the practicality and accuracy of the proposed modeling method.The TID effect model for digital ICs developed using this modeling technique includes both the logical function of the IC and changes in electrical properties and functional degradation impacted by TID,which has potential applications in the design of radiation-hardening tolerance in digital ICs.
基金funded by the National Natural Science Foundation of China (Nos.81771972,52171243,and 52371256)the National Key Research and Development Program of China (No.2017YFC0107405).
文摘X-ray excited photodynamic therapy(X-PDT)is the bravo answer of photodynamic therapy(PDT)for deep-seated tumors,as it employs X-ray as the irradiation source to overcome the limitation of light penetration depth.However,high X-ray irradiation dose caused organ lesions and side effects became the major barrier to X-PDT application.To address this issue,this work employed a classic-al co-precipitation reaction to synthesize NaLuF_(4):15%Tb^(3+)(NLF)with an average particle size of(23.48±0.91)nm,which was then coupled with the photosensitizer merocyanine 540(MC540)to form the X-PDT system NLF-MC540 with high production of singlet oxygen.The system could induce antitumor efficacy to about 24%in relative low dose X-ray irradiation range(0.1-0.3 Gy).In vivo,when NLF-MC540 irradiated by 0.1 Gy X-ray,the tumor inhibition percentage reached 89.5%±5.7%.The therapeutic mechanism of low dose X-PDT was found.A significant increase of neutrophils in serum was found on the third day after X-PDT.By immunohistochemical staining of tumor sections,the Ly6G^(+),CD8^(+),and CD11c^(+)cells infiltrated in the tumor microenvironment were studied.Utilizing the bilat-eral tumor model,the NLF-MC540 with 0.1 Gy X-ray irradiation could inhibit both the primary tumor and the distant tumor growth.De-tected by enzyme linked immunosorbent assay(ELISA),two cytokines IFN-γand TNF-αin serum were upregulated 7 and 6 times than negative control,respectively.Detected by enzyme linked immune spot assay(ELISPOT),the number of immune cells attributable to the IFN-γand TNF-αlevels in the group of low dose X-PDT were 14 and 6 times greater than that in the negative control group,respectively.Thus,it conclude that low dose X-PDT system could successfully upregulate the levels of immune cells,stimulate the secretion of cy-tokines(especially IFN-γand TNF-α),activate antitumor immunity,and finally inhibit colon tumor growth.
文摘Timer error as well as its convention is very important for dose accuracy during irradiation. This paper determines the timer error of irradiators at Secondary Standard Dosimetry Laboratory (SSDL) in Nigeria. The irradiators are Cs-137 OB6 irradiator and X-ray irradiators at the Protection level SSDL;and Co-60 irradiator at the Therapy Level SSDL. PTW UNIDOS electrometer and LS01 Ionization chamber were used at the Protection Level to obtain doses for both Cs-137 OB6 and X-ray irradiators while an IBA farmer type ionization chamber and an IBA DOSE 1 electrometer were used at the Protection Level SSDL. Single/multiple exposure method and graphical method were used in the determination of the timer error for the three irradiators. The timer error obtained for Cs-137 OB6 irradiator was 0.48 ± 0.01 s, the timer error for the X-ray irradiator was 0.09 ± 0.01 s while the timer error obtained for GammaBeam X200 was 1.21 ± 0.04 s. It was observed that the timer error is not affected by source to detector distance. It was also observed that the timer error of Co-60 Gamma X200 irradiator is increasing with the age of the machine. Source to detector distance and field size do not contribute towards the timer error of the irradiators. The timer error of the Co-60 Gamma X200 irradiator (the only irradiator among the irradiators with a pneumatic system) increases with the age of the irradiator.
文摘The Uranium-238 (<sup>238</sup>U), Thorium-232 (<sup>232</sup>Th) families and Potassium-40 (<sup>40</sup>K) are of terrestrial origin and contribute generally to an individual’s external exposure through our presence in this environment. They also contribute to the internal exposure through the ingestion of products and beverages such as water that are close to the earth. The aim of this work is to determine the committed effective dose or Total Indicative Dose (TID) due to gamma radioactivity of the borehole water from the Nord Riviera (NR) well field operated by the Côte d’Ivoire Water Distribution Company (SODECI) for the supply of drinking water to part of the population of Abidjan. In addition, the populations, with their habits, could use these borehole waters directly as drinking water. To this end, water samples from the seven (07) functional boreholes were collected and analyzed on a gamma spectrometry chain, equipped with an HPGe detector in the laboratory of the Radiation Protection Institute (RPI) of the GHANA Atomic Energy Commission (GAEC). The results of the specific activities of <sup>238</sup>U, <sup>232</sup>Th and <sup>40</sup>K obtained were transcribed into TID. As the natural radioactivity of the borehole water is high [1], the TIDs calculated from the activity results of the natural radionuclides<sup>238</sup>U, <sup>232</sup>Th, and <sup>40</sup>K vary for the seven boreholes from 0.150 to 0.166 mSv/yr with an average of 0.161 ± 0.034 mSv/yr. The TID of the control tower, where the borehole water is mixed and treated for household use, is equal to 0.136 ± 0.03 mSv/yr. The TIDs obtained are therefore all slightly greater than the WHO reference dose value of 0.1 mSv/yr. But all remain below the UNSCEAR reference dose of 0.29 mSv/yr.
文摘Objective: The current research study aims to calculate entrance surface air kerma for skull, chest, cervical spine, lumbar spine, and pelvic X-ray examinations in interior posterior and posterior interior positions and generate a method for chest dose reduction to decrease radiation risk. Materials and Methods: The indirect dose measurement was used in the current research. The X-ray tube output was measured using RAD-CHECK Plus ionization chamber and the indirect entrance surface air kerma was calculated via applying physical acquisition parameters such as a focus on skin distance, tube current times exposure time (mAs), and applied tube voltage (kV), and applying a mathematical model. Results: The main findings were obtained from comparing the radiation doses with the reference levels of International organizations such as the American College of Radiology and the International Atomic Energy Authority. The mean entrance skin dose for the skull (AP), skull (PA), skull (LAT), cervical spine (PA), cervical spine (LAT), lumbar spine (AP), lumbar spine (LAT), pelvis (AP), and pelvis (LAT) of adult X-ray examinations was within the diagnostic reference dose level values obtained by ACR (2018) except for the ESD for chest (AP) which was 0.88 mGy. Conclusions: The results of the study concluded that by adjusting the applied tube voltage, kV, and tube current product time, mAs decreased the radiation dose to the chest X-ray by 58%.
文摘Purpose: This study aimed to compare the survival benefits between different total radiation doses in definitive chemoradiotherapy (dCRT) for inoperable esophageal carcinoma (EC) based on modern radiotherapy techniques. Methods: A systematic review was performed by searching the databases of PubMed, EMBASE, Cochrane Central Register of Controlled Trials and Web of Science. All studies published prior to November 30, 2022, comparing radiation dose and disease-related outcomes in EC patients. The hazard ratio (HR) and odds ratio (OR) were used to describe the risk of outcomes and toxicities. Results: Seven prospective trials involving 1124EC patients were enrolled for analyses. The results revealed that the effect on overall survival (HR = 0.99, 95% CI = 0.85 - 1.16, P = 0.94), local progression-free survival (HR = 0.83, 95% CI = 0.58 - 1.17, P = 0.29), local regional progression-free survival (HR = 0.94, 95% CI = 0.76 - 1.17, P = 0.61), progression-free survival (HR = 0.90, 95% CI = 0.71 - 1.13, P = 0.35) was similar in the high-dose and standard-dose groups. Additionally, a high radiation dose exhibited a potential disadvantage in respiratory toxicities when compared with a standard dose (4.8% vs 2.2%, OR 2.11, P = 0.06). Conclusions: The efficacy of the HD group (≥60 Gy) and the SD group (approximately 50 Gy) for inoperable local advanced EC was similar. However, the HD group exhibited a high radiation dose exhibited a potential disadvantage in respiratory toxicities when compared with a standard dose. Simultaneously, the final results of several ongoing prospective trials regarding the optimal radiation dose in dCRT are awaited.
文摘Objective:To explore the half-effective dose(ED_(50))of remazolam toluenesulfonate combined with subthreshold amounts of esketamine for inhibiting cardiovascular response to tracheal intubation in elderly patients.Method:We included 42 patients,aged 65-75,who required general anesthesia and single-lumen endotracheal intubation for elective surgery.The first patient was administered remazolam toluenesulfonate at a dose of 0.20 mg/kg.Once the patient lost consciousness,their alertness/sedation score(OAA/S score)was≤1,and their BIS score was≤60,and a subthreshold dose(0.3 mg/kg)of esketamine was given.The subsequent doses were adjusted using a sequential approach based on the cardiovascular response to tracheal intubation observed in the previous patient.The dose was modified in increments or decrements of 0.01 mg/kg.The ED_(50)and 95%CI of remazolam toluenesulfonate were calculated using the Dixon and Massey sequential distribution test method.Result:The inhibition of endotracheal intubation response was positively correlated with the dose of remazolam toluenesulfonate,and the depth of sedation could not be achieved when the amount was≤0.22 mg/kg.The ED_(50)of remazolam toluenesulfonate combined with a subthreshold dose of esketamine in inhibiting cardiovascular response to tracheal intubation in elderly patients was 0.30(0.28,0.33)mg/kg.There was no statistically significant difference in blood pressure between the induction of anesthesia and before the operation.Conclusion:When compounded with 0.3 mg/kg esketamine,the ED_(50)of Remazolam toluenesulfonate in inhibiting cardiovascular response to endotracheal intubation in elderly patients was 0.30 mg/kg(95%CI0.28-0.33 mg/kg).
基金supported by the National Natural Science Foundation of China (Nos.11735003,11975041,and 11961141004)。
文摘In recent years,graphics processing units(GPUs)have been applied to accelerate Monte Carlo(MC)simulations for proton dose calculation in radiotherapy.Nonetheless,current GPU platforms,such as Compute Unified Device Architecture(CUDA)and Open Computing Language(OpenCL),suffer from cross-platform limitation or relatively high programming barrier.However,the Taichi toolkit,which was developed to overcome these difficulties,has been successfully applied to high-performance numerical computations.Based on the class II condensed history simulation scheme with various proton-nucleus interactions,we developed a GPU-accelerated MC engine for proton transport using the Taichi toolkit.Dose distributions in homogeneous and heterogeneous geometries were calculated for 110,160,and 200 MeV protons and were compared with those obtained by full MC simulations using TOPAS.The gamma passing rates were greater than 0.99 and 0.95 with criteria of 2 mm,2%and 1 mm,1%,respectively,in all the benchmark tests.Moreover,the calculation speed was at least 5800 times faster than that of TOPAS,and the number of lines of code was approximately 10 times less than those of CUDA or OpenCL.Our study provides a highly accurate,efficient,and easy-to-use proton dose calculation engine for fast prototyping,beamlet calculation,and education purposes.
基金supported by Natural Science Foundation of Beijing Municipality (Beijing Natural Science Foundation)(No.7191005)。
文摘Compton camera-based prompt gamma(PG) imaging has been proposed for range verification during proton therapy. However, a deviation between the PG and dose distributions, as well as the difference between the reconstructed PG and exact values, limit the effectiveness of the approach in accurate range monitoring during clinical applications. The aim of the study was to realize a PG-based dose reconstruction with a Compton camera, thereby further improving the prediction accuracy of in vivo range verification and providing a novel method for beam monitoring during proton therapy. In this paper, we present an approach based on a subset-driven origin ensemble with resolution recovery and a double evolutionary algorithm to reconstruct the dose depth profile(DDP) from the gamma events obtained by a cadmium-zinc-telluride Compton camera with limited position and energy resolution. Simulations of proton pencil beams with clinical particle rate irradiating phantoms made of different materials and the CT-based thoracic phantom were used to evaluate the feasibility of the proposed method. The results show that for the monoenergetic proton pencil beam irradiating homogeneous-material box phantom,the accuracy of the reconstructed DDP was within 0.3 mm for range prediction and within 5.2% for dose prediction. In particular, for 1.6-Gy irradiation in the therapy simulation of thoracic tumors, the range deviation of the reconstructed spreadout Bragg peak was within 0.8 mm, and the relative dose deviation in the peak area was less than 7% compared to the exact values. The results demonstrate the potential and feasibility of the proposed method in future Compton-based accurate dose reconstruction and range verification during proton therapy.
基金This work was supported by the National Natural Science Foundation of China(General Program)(Nos.12175114,U2167209)the Foundation of Key Laboratory of Metrology and Calibration Technology(No.JLKG2022001C001)+2 种基金the Platform Development foundation of China Institute for Radiation Protection(No.YP21030101)the National Key R&D Program of China(No.2021YFF0603600)the Tsinghua University Initiative Scientific Research Program(No.20211080081).
文摘Monte Carlo simulations are frequently utilized in radiation dose assessments.However,many researchers find the prevailing computing platforms to be intricate.This highlights a pressing need for a specialized framework for phantom dose evalua-tion.To address this gap,we developed a user-friendly radiation dose assessment platform using the Monte Carlo toolkit,Geant4.The Tsinghua University Phantom Dose(THUDosePD)augments the flexibility of Monte Carlo simulations in dosi-metric research.Originating from THUDose,a code with generic,functional,and application layers,THUDosePD focuses predominantly on anatomical phantom dose assessment.Additionally,it enables medical exposure simulation,intricate geometry creation,and supports both three-dimensional radiation dose analysis and phantom format transformations.The system operates on a multi-threaded parallel CPU architecture,with some modules enhanced for GPU parallel computing.Benchmark tests on the ICRP reference male illustrated the capabilities of THUDosePD in phantom dose assessment,covering the effective dose,three-dimensional dose distribution,and three-dimensional organ dose.We also conducted a voxelization conversion on the polygon mesh phantom,demonstrating the method’s efficiency and consistency.Extended applications based on THUDosePD further underline its broad adaptability.This intuitive,three-dimensional platform stands out as a valuable tool for phantom radiation dosimetry research.
基金supported by grants from the China Postdoctoral Science Foundation(Grant No.2022M712387)。
文摘Objective:To assess the clinical outcomes and toxicities of once daily(QD)simultaneous dose reduction intensity-modulated radiotherapy(SDR-IMRT-QD;SDR-QD)versus conventional QD IMRT(C-QD)and twice daily(BID)IMRT in patients with limited-stage small cell lung cancer(LS-SCLC).Methods:After propensity score matching(PSM),a retrospective analysis involving 300 patients with LS-SCLC treated using SDR-QD,C-QD,or BID was performed from January 1,2014 to December 31,2019.The prescribed irradiation dose in the SDR-QD cohort was 60 Gy/PGTV and 54 Gy/PTV QD.The radiation dose was 60 Gy for both PGTV and PTV QD in the C-QD cohort.The radiation dose was 45 Gy for both PGTV and PTV in the BID cohort.Toxicities,short-term effects,and survival outcomes were recorded.A meta-analysis on the protective effects of pharmaceuticals for cardiac toxicities induced by anti-tumor therapy was performed.Results:The median overall survival time(MST)in the 3 cohorts were 32.7 months(SDR-QD),26.3 months(C-QD),and 33.6 months(BID);the differences between groups were statistically significant.Lower toxicities and doses to organs-at-risk(OARs)occurred in the SDR-QD and BID cohorts.Further,the cardiac dose dosimetric parameter Vheart40 was negatively associated with survival(r=-0.35,P=0.007).A Vheart40 value of 16.5%was recommended as a cut-off point,which yielded 54.7%sensitivity and 85.7%specificity for predicting negative survival outcomes.The meta-analysis indicated that pharmaceuticals significantly reduced the cardiac toxicities induced by chemotherapy,but not radiotherapy.Conclusions:SDR-QD was shown to have similar toxicities and survival compared with BID,but fewer toxicities and better survival than C-QD.In addition,cardiac dose exposure was negatively associated with survival.Thus,16.5%of the cardiac dosimetric parameter Vheart40 is recommended as the cut-off point,and a Vheart40>16.5%predicts poor survival.
基金Project supported by the Science Challenge Project of China (Grant No.TZ2018004)the National Natural Science Foundation of China (Grant Nos.11975018 and 11775254)+1 种基金the National MCF Energy R&D Program of China (Grant No.2018YEF0308100)the outstanding member of Youth Innovation Promotion Association CAS (Grant No.Y202087)。
文摘The total ionizing dose(TID) effect is a key cause for the degradation/failure of semiconductor device performance under energetic-particle irradiation. We developed a dynamic model of mobile particles and defects by solving the rate equations and Poisson's equation simultaneously, to understand threshold voltage shifts induced by TID in silicon-based metal–oxide–semiconductor(MOS) devices. The calculated charged defect distribution and corresponding electric field under different TIDs are consistent with experiments. TID changes the electric field at the Si/SiO_(2) interface by inducing the accumulation of oxide charged defects nearby, thus shifting the threshold voltage accordingly. With increasing TID, the oxide charged defects increase to saturation, and the electric field increases following the universal 2/3 power law. Through analyzing the influence of TID on the interfacial electric field by different factors, we recommend that the radiation-hardened performance of devices can be improved by choosing a thin oxide layer with high permittivity and under high gate voltages.
文摘Workers who conduct regular facility inspections in radioactive environments will inevitably be affected by radiation.Therefore,it is important to optimize the inspection path to ensure that workers are exposed to the least amount of radiation.This study proposes a discrete Rao-combined artificial bee colony(ABC)algorithm for planning inspection paths with minimum exposure doses in radioactive environments with obstacles.In this algorithm,retaining the framework of the traditional ABC algorithm,we applied the directional solution update rules of Rao algorithms at the employed bee stage and onlooker bee stage to increase the exploitation ability of the algorithm and implement discretion using the swap operator and swap sequence.To increase the randomness of solution generation,the chaos algorithm was used at the initialization stage.The K-opt operation technique was introduced at the scout bee stage to increase the exploration ability of the algorithm.For path planning in an environment with complex structural obstacles,an obstacle detour technique using a recursive algorithm was applied.To evaluate the performance of the proposed algorithm,we performed experimental simulations in three hypothetical environments and compared the results with those of improved particle swarm optimization,chaos particle swarm optimization,improved ant colony optimization,and discrete Rao’s algorithms.The experimental results show the high performance of the proposed discrete Rao-combined ABC algorithm and its obstacle detour capability.
基金supported by the National Natural Science Foundation of China[grant numbers:NSFC81872597,81001239]。
文摘Objective The study aimed to estimate the benchmark dose(BMD)of coke oven emissions(COEs)exposure based on mitochondrial damage with the mitochondrial DNA copy number(mtDNAcn)as a biomarker.Methods A total of 782 subjects were recruited,including 238 controls and 544 exposed workers.The mtDNAcn of peripheral leukocytes was detected through the real-time fluorescence-based quantitative polymerase chain reaction.Three BMD approaches were used to calculate the BMD of COEs exposure based on the mitochondrial damage and its 95%confidence lower limit(BMDL).Results The mtDNAcn of the exposure group was lower than that of the control group(0.60±0.29 vs.1.03±0.31;P<0.001).A dose-response relationship was shown between the mtDNAcn damage and COEs.Using the Benchmark Dose Software,the occupational exposure limits(OELs)for COEs exposure in males was 0.00190 mg/m^(3).The OELs for COEs exposure using the BBMD were 0.00170 mg/m^(3)for the total population,0.00158 mg/m^(3)for males,and 0.00174 mg/m^(3)for females.In possible risk obtained from animal studies(PROAST),the OELs of the total population,males,and females were 0.00184,0.00178,and 0.00192 mg/m^(3),respectively.Conclusion Based on our conservative estimate,the BMDL of mitochondrial damage caused by COEs is0.002 mg/m^(3).This value will provide a benchmark for determining possible OELs.
文摘Computed Tomography(CT)images have been extensively employed in disease diagnosis and treatment,causing a huge concern over the dose of radiation to which patients are exposed.Increasing the radiation dose to get a better image may lead to the development of genetic disorders and cancer in the patients;on the other hand,decreasing it by using a Low-Dose CT(LDCT)image may cause more noise and increased artifacts,which can compromise the diagnosis.So,image reconstruction from LDCT image data is necessary to improve radiologists’judgment and confidence.This study proposed three novel models for denoising LDCT images based on Wasserstein Generative Adversarial Network(WGAN).They were incorporated with different loss functions,including Visual Geometry Group(VGG),Structural Similarity Loss(SSIM),and Structurally Sensitive Loss(SSL),to reduce noise and preserve important information on LDCT images and investigate the effect of different types of loss functions.Furthermore,experiments have been conducted on the Graphical Processing Unit(GPU)and Central Processing Unit(CPU)to compare the performance of the proposed models.The results demonstrated that images from the proposed WGAN-SSIM,WGAN-VGG-SSIM,and WGAN-VGG-SSL were denoised better than those from state-of-the-art models(WGAN,WGAN-VGG,and SMGAN)and converged to a stable equilibrium compared with WGAN and WGAN-VGG.The proposed models are effective in reducing noise,suppressing artifacts,and maintaining informative structure and texture details,especially WGAN-VGG-SSL which achieved a high peak-signalto-noise ratio(PNSR)on both GPU(26.1336)and CPU(25.8270).The average accuracy of WGAN-VGG-SSL outperformed that of the state-ofthe-art methods by 1 percent.Experiments prove that theWGAN-VGG-SSL is more stable than the other models on both GPU and CPU.
基金National Natural Science Foundation of China(12205028)Natural Science Foundation of Sichuan Province(2022NSFSC1235)Young and Middle-aged Backbone Teacher Foundation of Chengdu University of Technology(10912-JXGG2022-08363)。
文摘Laser-assisted simulation technique has played a crucial role in the investigation of dose rate effects of silicon-based devices and integrated circuits,due to its exceptional advantages in terms of flexibility,safety,convenience,and precision.In recent years,wide band gap materials,known for their strong bonding and high ionization energy,have gained increasing attention from researchers and hold significant promise for extensive applications in specialized environments.Consequently,there is a growing need for comprehensive research on the dose rate effects of wide band gap materials.In response to this need,the use of laser-assisted simulation technology has emerged as a promising approach,offering an effective means to assess the efficacy of investigating these materials and devices.This paper focused on investigating the feasibility of laser-assisted simulation to study the dose rate effects of wide band gap semiconductor devices.Theoretical conversion factors for laser-assisted simulation of dose rate effects of GaN-based and SiC-based devices were been provided.Moreover,to validate the accuracy of the conversion factors,pulsed laser and dose rate experiments were conducted on GaN-based and SiC-based PIN diodes.The results demonstrate that pulsed laser radiation andγ-ray radiation can produce highly similar photocurrent responses in GaN-based and SiC-based PIN diodes,with correlation coefficients of 0.98 and 0.974,respectively.This finding reaffirms the effectiveness of laser-assisted simulation technology,making it a valuable complement in studying the dose rate effects of wide band gap semiconductor devices.
文摘BACKGROUND Treatment of infantile-onset inflammatory bowel disease(IO-IBD)is often challenging due to its aggressive disease course and failure of standard therapies with a need for biologics.Secondary loss of response is frequently caused by the production of anti-drug antibodies,a well-known problem in IBD patients on biologic treatment.We present a case of IO-IBD treated with therapeutic drug monitoring(TDM)-guided high-dose anti-tumor necrosis factor therapy,in which dose escalation monitoring was used as a strategy to overcome anti-drug antibodies.CASE SUMMARY A 5-mo-old boy presented with a history of persistent hematochezia from the 10th d of life,as well as relapsing perianal abscess and growth failure.Hypoalbuminemia,anemia,and elevated inflammatory markers were also present.Endoscopic assessment revealed skip lesions with deep colic ulcerations,inflammatory anal sub-stenosis,and deep fissures with persistent abscess.A diagnosis of IO-IBD Crohn-like was made.The patient was initially treated with oral steroids and fistulotomy.After the perianal abscess healed,adalimumab(ADA)was administered with concomitant gradual tapering of steroids.Clinical and biochemical steroid-free remission was achieved with good trough levels.After 3 mo,antibodies to ADA(ATA)were found with undetectable trough levels;therefore,we optimized the therapy schedule,first administering 10 mg weekly and subsequently up to 20 mg weekly(2.8 mg/kg/dose).After 2 mo of high-dose treatment,ATA disappeared,with concomitant high trough levels and stable clinical and biochemical remission of the disease.CONCLUSION TDM-guided high-dose ADA treatment as a monotherapy overcame ATA production.This strategy could be a good alternative to combination therapy,especially in very young patients.
